• Korean journal of food and cookery science
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• v.29 no.1
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• pp.53-62
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• 2013

Lipid oxidation and antioxidants changes in perilla oil emulsion added with chlorophyll were studied during storage in the dark or under 1,700 lux light at $25^{\circ}C$ for 48 h. The emulsion was consisted of perilla oil (33.12 g), 5% acetic acid (66.23 g), egg yolk powder (0.5 g), and xanthan gum (0.15 g), and Chlorophyll b was added to the emulsion at 0, 2.5 and 4 mg/kg. The lipid oxidation was evaluated by headspace oxygen consumption and hydroperoxide formation, and tocopherols and polyphenols were monitored by HPLC and spectrophotometry at 725 nm, respectively. The lipid oxidation of the perilla oil emulsion in the dark was not significant regardless of the addition of chlorophyll. Light increased and accelerated the lipid oxidation of the emulsion, and increased addition level of chlorophyll under light increased it further. However, there was no significant change in fatty acid composition in any case. Contents of tocopherols and polyphenols in the emulsion were not significantly changed during storage in the dark regardless of chlorophyll addition, indicating their little degradation. Tocopherols and polyphenols in the emulsion were significantly degraded during storage of the emulsion under light, and the degradation rate of polyphenols was increased with addition level of chlorophyll. The lipid oxidation of the perilla oil emulsion was inversely related with the residual amounts of tocopherols and polyphenols, with more dependent on the retention of polyphenols than that of tocopherols.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.88-96
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• 2021

When oil tankers, large passenger ships and cargo ships sink under the sea owing to various maritime accidents, the residual cargo oil or fuel oil in the such vessels could pose direct risk to factor for the marine environment and it require safe and rapid removal. Although domestic and foreign salvage companies are adopting various recovery methods and technologies with customizations according to each site during recovery operations studies on reasonable assessment modules for the operation process are relatively insufficient. In this study, the data from trapped-oil recovery operations performed at different site conditions were collected and analyzed in order to designed an operation assessment module, define the operational process steps in terms of preparation, implementation and completion, and derive key factors for each detailed process. Subsequently, the module was designed in such a way as to construct performance indicators to assess these key factors. In order to exclude subjective opinions from the assessment as much as possible, the assessment each item was constructed with indicators based on data that could be evaluated quantitatively and its usefulness was verified by applying the module to the trapped-oil recovery operation cases. We expect this the method and the technology assessment module for the trapped-oil recovery operation on sunken vessels will help to verify the adequacy of the trapped-oil recovery such operation before or after. Furthermore, it is expected that the continuous accumulation of assessment data and feedback from past or future operation cases will contribute toward enhancing the overall safety, efficiency and field applicability of trapped-oil recovery operation.

• Tribology and Lubricants
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• v.10 no.2
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• pp.51-55
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• 1994

Rolling friction test was carried out to investigate the effect of the wear amount on rolling contact fatigue process in lubrication oil. The methods of this process were conducted at two Hertzian contact pressure and three slide ratio in each case by employing normalized and annealed carbon steel. During process of the rolling contact fatigue, the number of rotation until surface damage was occurred, the wear amount of rolling contact surface, and residual stress and half-value breadth using X-ray reflection on rolling contact surface were investigated. The result of this study shows that rolling contact fatigue process was directly influenced by wear trend and was confirmed by change of residual stress and half-value breadth on rolling contact surface.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.962-967
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• 2003

Recently, environmental pollution has become a serious problem in industry, and many researches have been done in order to preserve the environment. The coolant, which promotes lubrication, cooling and penetration, contains chlorine, sulfur and phosphorus to improve the machining efficiency. These additives, which move around into the air during machining, pollute working. Therefore, many researches on how to reduce the amount of coolant during machining have been carried out. However, to reduce even small amount of coolant causes high temperature of a workpiece and it brings thermal defects. In this study, the experiments of wet & dry grinding using cooling methods (using coolant only, mist and compressed cold air only) are performed to solve the problem of environmental contamination and to get a better surface integrity of a workpiece by comparing surface roughness, roundness and residual stress.

• Tribology and Lubricants
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• v.10 no.3
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• pp.71-77
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• 1994

Rolling friction test was carried out to investigate the effect of the wear amount on rolling contact fatigue process in lubrication oil. The methods of this process were conducted at two Hertzian contact pressure and three slide ratio in each case by employing normalized and annealed carbon steel. During process of the rolling contact fatigue, the number of rotation until surface damage was occurred, the wear amount of rolling contact surface, and residual stress and half-value breadth using X-ray reflection on rolling contact surface were investigated. The result of this study shows that rolling contact fatigue process was directly influenced by wear trend and was confirmed by change of residual stress and half-value breadth on rolling contact surface.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.50-57
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• 2006

The investigation of microscopic precision in high speed endmilling is necessary for machinability evaluation, and the environmentally conscious machining technology have more important position in recent machining process. The microscopic precision of workpiece is influenced by machining environments variation as cutting fluid type and lubricant method. In this study, the cutting forces according to variation of cooling and lubrication are investigated by specially designed tool dynamometer. And the surface roughness, micro hardness and residual stress are evaluated according to machining environment. The characteristics of damaged layer in environmentally conscious machining and conventional machining using cutting fluid are compared experimentally.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.253-256
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• 2001

Irradiation of food is not only used for sanitation purposes but can be used for processing techniques to reduce or eliminate toxic or undesirable compounds on food. Irradiation wag effective to reduce the allergenicity of food by modification of the structure of proteins causing allergy reactions. Volatile N-nitrosmaine was reduced or eliminated by irradiation in the model system study and the breakdown products by irradiation did not recombine under human stomach conditions (pH 2,3, and 4,37$^{\circ}C$). The possibility of residual chlorophyll b reduction by irradiation was also found, and the model study indicated that irradiation be used to destroy chlorophyll b, resulting in protection from photooxidation in oil without acceleration of lipid oxidation during irradiation. In this paper, several on-going research projects for the application of food irradiation as a new processing technique are introduced, including reduction of food allergens, breakdown of volatile N-nitrosamine and residual chlorophyll b.

• Current Optics and Photonics
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• v.7 no.5
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• pp.511-517
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• 2023

Pipelines play an important role in urban water supply and drainage, oil and gas transmission, etc. This paper presents a technique for pattern recognition of fiber optic vibration signals collected by a distributed vibration sensing (DVS) system using a deep learning residual network (ResNet). The optical fiber is laid on the pipeline, and the signal is collected by the DVS system and converted into a 64 × 64 single-channel grayscale image. The grayscale image is input into the ResNet to extract features, and finally the K-nearest-neighbors (KNN) algorithm is used to achieve the classification and recognition of pipeline damage.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.5
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• pp.1-8
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• 2009

Solenoid valve cleaner is used for clean the solenoid valve in automatic transmission for a car when it is clogged with transmission oil sludge. Nevertheless when the solenoid is turned off, the residual current in the solenoid coil makes slow motion of the plunger in the solenoid which makes lower in cleansing performance and speed. In this paper, the method of performance Improvement for solenoid valve cleaner is proposed. The residual current in the solenoid coil is eliminated rapidly by the proposed method and it improves the cleansing performance and speed. The experimental results show the validity of the reposed method.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.639-643
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• 2007

The use of forest biomass resources produced by forest tending and residual forest biomass that was not gathered on commercial thinning or cutting area was estimated to be come into the spotlight as bioenergy sources in these days of new high oil price. With considering these problems, This study was investigated about possibility with biomass calculation and convertibility to fossil fuel in these area. Total forest tending area in the year 2005 was 294, 115 ha and the yield gathered from these area was $143,747m^3$. It is equivalent to biomass of 115,000 ton and caloric value of 533,199Gcal. However, the potential and additional yield that is residual in forest stands was 2,483,000 ton. It is equivalent to 11,133 billion won of oil which is 20 times of the actual yield produced by forest tending. Therefore, these amount of biomass has a substitution effect of the fossil fuel. Moreover, the residual biomass that is not gathered at commercial thinning and cutting area was 475,000 ton. It is equivalent to 2,206,235 Gcal of heating value and about 2,211 billion won of oil. This potential amount could be a new energy source to be a substitution effect of fossil fuel. It is time to be interested in the forest biomass as a renewable and environment-friendly resource and its substitution effect of fossil fuel.